NOTES BY THE EDITOR. V 



but it is to be hoped that theoretical fears on this subject will soon 

 be dissipated by successful experience. The use of petroleum as 

 a fuel for steam engines seems to be approaching practical appli- 

 cation. 



The substitution of steel for iron in various parts of locomotives, 

 and for rails, has added gi-eatly to the permanence of the ma- 

 chinery, and diminished the wear and tear in a remarkable de- 

 gree. The extensive use of steel in ship-building, esijecially 

 since the Bessemer process has come into vogue, has contril)uted 

 much to the strength and safety of sea-going vessels, with dimin- 

 ished weight, and seems likely to restrict the composite system 

 of v/ood and iron construction to those navigating smooth waters. 



The battle of the guns versus armoi'-jjlates is still waged with 

 great vigor, and the-victory just now appears to be on the side of 

 the steel projectiles and chilled shot of Maj. Palliser and others; 

 but this will only give rise to improved machinery, a better selec- 

 tion of material, and better processes of manufacture on the part 

 of the armor-plate makers. 



The new gunpowder of Capt. Schultze, made from wood, by a 

 process similar to that of making gun-cotton, bids fair to rival the 

 old explosive for certain purposes. Nitroglycerine and gun-paper 

 have also been successfully introduced, the former for blasting, 

 and the latter for small arms. 



In respect to light, heat, chemical affinity, electricity, and mag- 

 netism, universal attributes of matter in all its forms, it may be 

 considered as proved that all these forces are so invariably con- 

 nected inter se and with motion, as to be regarded as modifications 

 of each other, and as resolving themselves objectively into mo-' 

 tion, and subjectively into that something which produces or 

 resists motion, and which we call force. 



Recent researches go to show that magnetism is cosmical, and 

 not merely terrestrial. One of the startling suggestions made by 

 Mayer, as a consequence resulting from the dynamical theory of 

 heat, is that, by the loss of the vis viva occasioned by friction of 

 the tidal waves, as well as by their forming a drag upon the 

 earth's rotary movement, the velocity of the earth's rotation must 

 be gradually diminishing, and that thus, unless some undiscovered 

 compensatory action exist, this rotation must ultimately cease, and 

 changes hardly calculable take place in the solar system. M. De- 

 launay and Mr. Airy consider that part of the acceleration of the 

 moon's mean motion, not at present accounted for by planetary 

 1* 



